Display device

Abstract

To provide a display device or the like in which a resin can be stably cured.SOLUTION: A display device including a first circuit and a second circuit over one substrate, in which the first circuit has a function of performing display, the second circuit has a function of driving the first circuit, the second circuit includes a transistor and a capacitor, and the transistor includes an oxide semiconductor layer over a first insulator layer, the capacitor includes a first conductive layer, a second insulating layer, and a second conductive layer, the first conductive layer is provided over the first insulator layer, one of a source and a drain of the transistor is electrically connected to the second conductive layer, and the first conductive layer includes the same metal element as the oxide semiconductor layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention relates to a display device.

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field relates to an article, a method, or a manufacturing method. , process, machine, manufacture, or composition of matter Therefore, one embodiment of the present invention disclosed in this specification more specifically relates to The technical fields include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, and their driving Examples of the method include a method for operating the device and a method for manufacturing the device. [Background technology]

[0003] Display devices that have a display area (pixel section) and peripheral circuits (drive section) on the same substrate are becoming more common. For example, Patent Document 1 discloses a method for manufacturing a display device using a transistor made of an oxide semiconductor in a display region and a peripheral circuit. The technology adopted in the road is disclosed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2007-123861 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, a display area (pixel section) and a peripheral circuit (drive section) are integrated on the same substrate using liquid crystal elements. In the manufacture of a display device having such a structure, one substrate and the other substrate are bonded together using a resin. After being applied to the substrate, the resin is cured in various ways. Sufficient curing is required.

[0006] An object of one aspect of the present invention is to provide a display device or the like that allows stable curing of a resin. It shall be one.

[0007] Another embodiment of the present invention is to provide a display device or the like that can be manufactured inexpensively and with improved productivity. One of the challenges is to

[0008] Alternatively, one embodiment of the present invention is to increase the capacitance without increasing the area of ​​the capacitor portion. One of the objects is to provide a display device or the like that can

[0009] Another object of one embodiment of the present invention is to provide a high-resolution display device.

[0010] Another object of one embodiment of the present invention is to provide a lightweight display device.

[0011] Another object of one embodiment of the present invention is to provide a highly reliable display device.

[0012] Another object of one embodiment of the present invention is to provide a display device that can reduce power consumption. This is one of the topics.

[0013] Another object of one embodiment of the present invention is to provide a large-area display device.

[0014] Another object of one embodiment of the present invention is to provide a novel display device or the like.

[0015] The description of these problems does not preclude the existence of other problems. It is not necessary for the present invention to solve all of these problems. The above will be made clear from the description, drawings, claims, etc. It is possible to extract other issues from the descriptions in the patent, claims, etc. [Means for solving the problem]

[0016] One embodiment of the present invention is a display device in which a first circuit and a second circuit are provided over the same substrate. The first circuit has a function of displaying, and the second circuit has a function of driving the first circuit. The second circuit has a transistor and a capacitor element, and the transistor is connected to the first insulating The capacitor element has an oxide semiconductor layer formed on a first conductive layer and a second insulating layer. and a second conductive layer, the first conductive layer being provided on the first insulating layer, One of the source and drain of the transistor is electrically connected to the second conductive layer, and the first conductive layer The display device is characterized in that the oxide semiconductor layer contains the same metal element as the oxide semiconductor layer.

[0017] In the display device, the first conductive layer and the second conductive layer may be light-transmitting. do.

[0018] In the display device, the first conductive layer has a region with a higher hydrogen concentration than the oxide semiconductor layer. It can have a range.

[0019] In the display device, the second insulating layer can include a silicon nitride film.

[0020] In the display device, the first circuit can have a liquid crystal element.

[0021] In the display device, the first circuit can have an organic EL element.

[0022] One embodiment of the present invention is a display device in which a first circuit and a second circuit are provided over the same substrate. The first circuit has a function of displaying, and the second circuit has a function of driving the first circuit. The second circuit has a transistor, a first capacitor, and a second capacitor. The first capacitor element has an oxide semiconductor layer provided on a first insulator layer. The second capacitance element has a first conductive layer, a first insulating layer, and a second conductive layer. a first conductive layer, a second insulating layer, and a third conductive layer, the second conductive layer being disposed on the first insulating layer; One of the source and drain of the transistor is electrically connected to the second conductive layer. The first conductive layer and the third conductive layer are electrically connected, and the first conductive layer is made of an oxide. The display device is characterized by having the same metal element as the semiconductor layer.

[0023] In the display device, the first conductive layer, the second conductive layer, and the third conductive layer are transparent. It can have a photosensitive property.

[0024] Another embodiment of the present invention is a display device including the display device and a printer electrically connected to the display device. The display module is characterized by having a backing substrate.

[0025] Other aspects of the present invention will be described in the following embodiments and is shown in the drawings. [Effects of the Invention]

[0026] One embodiment of the present invention can provide a display device or the like that allows stable curing of a resin. .

[0027] Another embodiment of the present invention is to provide a display device or the like that can be manufactured inexpensively and with improved productivity. It is possible.

[0028] Alternatively, one embodiment of the present invention is to increase the capacitance without increasing the area of ​​the capacitor portion. It is possible to provide a display device etc. that can

[0029] Alternatively, one embodiment of the present invention can provide a high-resolution display device.

[0030] Alternatively, one embodiment of the present invention can provide a lightweight display device.

[0031] Alternatively, according to one embodiment of the present invention, a highly reliable display device can be provided.

[0032] Another embodiment of the present invention can provide a display device that can reduce power consumption. Cut.

[0033] Alternatively, one embodiment of the present invention can provide a large-area display device.

[0034] Alternatively, one embodiment of the present invention can provide a novel display device or the like.

[0035] The description of these effects does not preclude the existence of other effects. The embodiment does not necessarily have to have all of these effects. , the specification, drawings, claims, etc., and It is possible to extract other effects from the claims and other descriptions. [Brief explanation of the drawings]

[0036] [Figure 1] 1A and 1B are a circuit diagram and a top view illustrating a display device of one embodiment of the present invention. [Figure 2] 1A and 1B are cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 3]1A and 1B are cross-sectional views illustrating transistors according to embodiments of the present invention. [Figure 4] 1A and 1B are cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 5] 1A and 1B are top views illustrating the configuration of a circuit according to one embodiment of the present invention. [Figure 6] 1A and 1B are top views illustrating the configuration of a circuit according to one embodiment of the present invention. [Figure 7] 1A and 1B are a top view and a cross-sectional view illustrating a display device of one embodiment of the present invention. [Figure 8] 1A and 1B are a top view and a cross-sectional view illustrating a display device of one embodiment of the present invention. [Figure 9] 1A and 1B are cross-sectional views illustrating transistors according to embodiments of the present invention. [Figure 10] 1A and 1B are a top view and a cross-sectional view illustrating a display device of one embodiment of the present invention. [Figure 11] 1A and 1B are a top view and a circuit diagram illustrating a display device of one embodiment of the present invention. [Figure 12] 1A to 1C illustrate electronic devices according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiments, and various changes and modifications may be made in the form and details thereof without departing from the spirit and scope of the present invention. It will be readily understood by those skilled in the art that the present invention can be achieved by the following embodiments. It should not be construed as being limited to the contents of the description. The same reference numerals are used in different drawings to denote the same parts or parts having similar functions. A repeated explanation will be omitted.

[0038] The words "film" and "layer" may be used interchangeably depending on the situation. For example, the term "conductive layer" can be replaced with "conductive film." ". Alternatively, for example, the term "insulating film" may be used. It may be possible to change the term to "insulating layer."

[0039] In this specification, a transistor is a small element including a gate, a drain, and a source. It is an element with at least three terminals. A channel is formed between the source (source terminal, source region or drain electrode) and the source (source terminal, source region or source electrode). The transistor has a drain region, a channel region, and a source region, and a current can flow through the drain region, a channel region, and a source region. This is what is done.

[0040] Here, the source and drain vary depending on the structure or operating conditions of the transistor. Therefore, it is difficult to determine which is the source and which is the drain. The part that functions as a source and the part that functions as a drain are not called source or drain. One of the source and the drain is referred to as a first electrode, and the other of the source and the drain is referred to as a second electrode. It may be written.

[0041] In this specification, the ordinal numbers "first," "second," and "third" are used to avoid confusion of the elements. It should be noted that the numbers are added to avoid confusion and are not intended to be limiting.

[0042] In this specification, "A and B are connected" does not mean that A and B are directly connected. In addition to those that are electrically connected, A and B are also included. Connected to means that there is an object that has some electrical effect between A and B. When this occurs, it refers to something that enables the transmission and reception of electrical signals between A and B.

[0043] For example, if the source (or first terminal, etc.) of the transistor is connected via Z1 (or (not shown), electrically connected to X, and the drain (or second terminal, etc.) of the transistor is connected to Z 2 (or not), and is electrically connected to Y, or the source of the transistor (or the first terminal, etc.) is directly connected to a part of Z1, and another part of Z1 is directly connected to X. The drain (or second terminal, etc.) of the transistor is directly connected to a part of Z2. and another part of Z2 is directly connected to Y, It is possible to do so.

[0044] For example, "X and Y and the source (or first terminal, etc.) and drain (or second terminal, etc.) of a transistor" The terminals of the transistor (or the first terminal) are electrically connected to each other. 1 terminal, etc.), the drain of the transistor (or the second terminal, etc.), and Y. It can be expressed as "connected to the source (or the first The first terminal of the transistor is electrically connected to X, and the drain of the transistor is electrically connected to the second terminal of the transistor. The transistor source (or first terminal, etc.) is electrically connected to Y, and the transistor source (or first terminal, etc.) is electrically connected to X. The drain (or second terminal, etc.) of the transistor, Y, is electrically connected in this order. " Alternatively, "X is the source (or first terminal, etc.) of the transistor. and the drain (or second terminal, etc.) are electrically connected to Y, and X, the source (or first terminal, etc.) of a transistor, the drain (or second terminal, etc.) of a transistor ), Y is provided in this order of connection. By specifying the order of connections in the circuit configuration using a simple expression method, Distinguish between the source (or first terminal, etc.) and the drain (or second terminal, etc.) of a transistor. The technical scope can be determined by the above.

[0045] Alternatively, for example, "the source (or first terminal, etc.) of a transistor" is electrically connected to X through at least a first connection path, and the first connection path is , and the second connection path is a transistor through a transistor. The source (or first terminal, etc.) of the transistor and the drain (or second terminal, etc.) of the transistor The first connection path is a path via Z1, and the second connection path is a path between the first and second transistors. The drain (or second terminal, etc.) of the capacitor is electrically connected to Y through at least a third connection path. the third connection path does not have the second connection path, and the third connection path The connection path is the path via Z2. The source (or first terminal, etc.) of the resistor is connected to the resistor via Z1 by at least the first connection path. and electrically connected to X, and the first connection path does not have a second connection path; The second connection path has a connection path through a transistor, and (or the second terminal, etc.) is connected to Y via Z2 by at least a third connection path. The third connection path does not have the second connection path. Alternatively, the source (or first terminal, etc.) of the transistor may be at least The first electrical path is electrically connected to X through Z1. The primary path does not have a second electrical path, and the second electrical path is a From the source (or first terminal, etc.) to the drain (or second terminal, etc.) of the transistor The drain (or second terminal, etc.) of the transistor is connected to at least a third The third electrical path is electrically connected to Y through Z2. , does not have a fourth electrical path, and the fourth electrical path is (or second terminal, etc.) to the source (or first terminal, etc.) of the transistor. Using the same expression as these examples, the circuit configuration By defining the connection path in Distinguishing between the first terminal (or the second terminal, etc.) and the drain (or the second terminal, etc.) to determine the technical scope. can be done.

[0046] These representation methods are merely examples, and the present invention is not limited to these representation methods. , Y, Z1, Z2 are objects (e.g., devices, elements, circuits, wiring, electrodes, terminals, conductive films, layer, etc.).

[0047] In this specification, terms indicating arrangement such as "above" and "below" refer to the positions of components. The relationship is used for convenience in explaining the relationship with reference to the drawings. The values ​​change depending on the direction in which each component is depicted. It is not limited to words and phrases, and can be rephrased appropriately depending on the situation.

[0048] In this specification, "parallel" means that two straight lines are arranged at an angle of -10° or more and 10° or less. Therefore, it includes the case of -5° or more and 5° or less. "Line" refers to the state in which two straight lines are arranged at an angle between -30° and 30°. "Perpendicular" means that two straight lines are arranged at an angle of 80° or more and 100° or less. Therefore, it also includes the case where the angle is between 85° and 95°. This refers to a state in which two straight lines are arranged at an angle of 60° or more and 120° or less.

[0049] In addition, in this specification, when the crystal is a trigonal or rhombohedral crystal, it is expressed as a hexagonal crystal system. .

[0050] (Embodiment 1) In this embodiment, a configuration example of a display device will be described.

[0051] (About the circuit and top view in Figure 1) FIG. 1(A) shows a display device 10. In this specification, the display device 10 is, for example, a liquid crystal display (LCD) device. The display device 10 is a device having a display element such as a liquid crystal element. The display device 10 includes a circuit 20 and a circuit 30. The circuit 20 can mainly constitute a display area including pixels. For example, the circuit 30 can drive and control the circuit 20. The circuit 30 may function as a protection circuit or an inspection circuit. At least one of a gate driver, a protection circuit, a precharge circuit, and an inspection circuit The circuit 30 may be located on one side of the circuit 20 or on both sides. The display device 10 may also have a circuit 40 on the same substrate. The circuit 40 can drive and control the circuit 20 in the same manner as the circuit 30. The display device 10 is at least one of a driver, a selector switch, etc. A control circuit, a power supply circuit, a signal generating circuit, an optical sheet, and a touch sensor are arranged on a separate substrate. , a touch sensor drive circuit, an optical sensor, a backlight, or a frame, etc. The display device may further include one of the display panels or display modules. 10 may also be configured without circuitry 40 on the same substrate.

[0052] 1B shows a basic circuit diagram of a pixel circuit included in the circuit 20. The circuit 20 includes a transistor, a capacitor, and a liquid crystal element. A cross-sectional view of the circuit 20 taken along the dashed line A-A' is shown in FIG.

[0053] Similarly, FIG. 1C shows a circuit diagram illustrating a part of the configuration of the circuit 30. FIG. 1E shows a circuit 2B shows a cross-sectional view of the circuit 30 taken along the dashed line B-B' in the top view of the circuit 30. The circuit shown in Figure 1(C) can function as a part of a buffer circuit, for example. The transistor 11, the transistor 12, the transistor 13, and the capacitance element C1 In FIG. 1C, the capacitor C1 is connected to the gate source of the transistor 12. However, one aspect of the present invention is not limited to this. In FIG. 1(C), VDD, VSS, CLK, etc. However, one embodiment of the present invention is not limited to this. Other signals or potentials may be supplied.

[0054] <About the cross-sectional view of the display device> A cross-sectional view of the display device 10 will be described with reference to Fig. 2. The display device 10 mainly comprises a liquid crystal display (LCD). However, the display element is a liquid crystal element using a liquid crystal. The display element is not limited to this, and other display elements such as an organic EL element may also be used.

[0055] The display device is composed of the components provided between the substrate 100 and the substrate 300. A liquid crystal element 330 is provided between the liquid crystal display panel 10 and the substrate 300 (see FIG. 2A).

[0056] The liquid crystal layer 200 is sealed with an adhesive layer 400 provided between the substrate 100 and the substrate 300 . At least a portion of the adhesive layer 400 is in contact with a small portion of the circuit 30 as shown in FIGS. 1(A) and 2(B). At least a part of the elements of the circuit 30 is provided. The adhesive layer 400 and at least a part of the circuit 30 may overlap each other. The adhesive layer 400 and at least a part of the circuit 30 may be in the vicinity of each other. It may be configured so that the

[0057] Circuit 20 First, the cross-sectional structure of a pixel portion included in the circuit 20 will be described with reference to FIG.

[0058] A transistor 60 and a capacitor 70 are provided over a substrate 100 .

[0059] Transistor 60 The transistor 60 comprises an insulating layer 110, a conductive layer 120, an insulating layer 130, and a semiconductor layer 14. 0, conductive layer 150, conductive layer 160, insulating layer 170, and insulating layer 180. The layer 120 functions as a gate electrode. The insulating layer 130 functions as a gate insulating film. The semiconductor layer 140 has a function as a semiconductor layer having a channel formation region. The conductive layer 150 functions as one of a source electrode and a drain electrode. The layer 160 functions as the other of the source and drain electrodes. , and is connected to the conductive layer 190. The insulating layer 170 is used to protect the channel portion. The insulating layer 180 can be used to prevent impurities from diffusing. .

[0060] In FIG. 2A, the area of ​​the upper surface of the semiconductor layer 140 is the same as the area of ​​the upper surface of the conductive layer 120. , or preferably small.

[0061] In FIG. 2A, a conductive layer 120, an insulating layer 130, a semiconductor layer 140, a conductive layer 150, or Although the conductive layer 160 is shown as a single layer, it may be a laminate of two or more layers. The laminate may be made of different materials or the same material.

[0062] The transistor 60 shown in FIG. 2A is a transistor with a bottom gate structure. 2A shows a modified example of the transistor 60. Although the transistor 60 is shown as a channel etch type, as shown in the cross-sectional view of FIG. As shown in the cross-sectional view of FIG. 3(B), a channel protection type in which an insulating layer 165 is provided may be used. It is also possible to make the transistor have a top gate structure.

[0063] In the off state, the transistor 60 connected to the display element (for example, the liquid crystal element 330) By using a transistor with extremely low leakage current, it is possible to hold the image signal. For example, if the image signal is written at 11.6 μHz (1 day), the time that can be A frequency of 0.28mHz (1 time per second) or more and less than 0.1Hz (0.1 times per second) is preferable. Images can be retained even if the frequency is more than 1Hz (once per hour) but less than 1Hz (once per second). This reduces the frequency of writing image signals. Of course, the power consumption of the image signal writing device 10 can be reduced by setting the writing rate to 1 Hz or less. Preferably, the frequency is 30Hz (30 times per second) or higher, more preferably 60Hz (6 times per second). The frequency can be greater than or equal to 960Hz (960 times per second) and less than 960Hz (960 times per second).

[0064] As a transistor with extremely small leakage current in an off state, for example, an oxide A transistor using a semiconductor for a semiconductor layer can be used. Indium (In), zinc (Zn) and M (Al, Ga, Ge, Y, Zr, Sn, La, oxide semiconductors, including materials represented by In-M-Zn oxides containing metals such as Ce or Hf A conductor can be suitably used for the semiconductor layer.

[0065] In a transistor using an oxide semiconductor for a semiconductor layer, for example, When the voltage is set to about 0.1V, 5V, or 10V, the transistor channel width is It is possible to reduce the rated off-current to several yA / μm to several zA / μm.

[0066] Oxide semiconductors The oxide semiconductor used as the semiconductor layer 140 is, for example, an In—Ga—Zn-based oxide. In-Al-Zn oxides, In-Sn-Zn oxides, In-Hf-Zn oxides , In-La-Zn oxide, In-Ce-Zn oxide, In-Pr-Zn oxide, In-Nd-Zn oxide, In-Sm-Zn oxide, In-Eu-Zn oxide, I n-Gd-Zn oxide, In-Tb-Zn oxide, In-Dy-Zn oxide, In -Ho-Zn oxide, In-Er-Zn oxide, In-Tm-Zn oxide, In- Yb-Zn oxide, In-Lu-Zn ​​oxide, In-Sn-Ga-Zn oxide, I n-Hf-Ga-Zn oxide, In-Al-Ga-Zn oxide, In-Sn-Al- Zn-based oxides, In-Sn-Hf-Zn-based oxides, In-Hf-Al-Zn-based oxides, I An n-Ga-based oxide can be used.

[0067] Here, the In-Ga-Zn oxide is a material containing In, Ga, and Zn as main components. It means oxide, and the ratio of In, Ga, and Zn does not matter. Other metal elements may also be included.

[0068] For the above reasons, power consumption can be reduced by using a transistor including an oxide semiconductor. A display device can be fabricated.

[0069] <Capacitor element 70> The capacitor 70 includes a conductive layer 190, an insulating layer 180, and a conductive layer 210. The conductive layer 190 functions as one electrode of the capacitor 70. The conductive layer 190 functions as the other electrode of the conductive layer 70. An edge layer 180 is provided. A conductive layer 190 is connected to the transistor 60.

[0070] The conductive layer 210 is formed on the insulating layer 130 as well as the semiconductor layer 140 .

[0071] The transistor 60 may be a transistor in which an oxide semiconductor is used for the semiconductor layer 140. By doing so, the conductive layer 210 can be formed on the insulating layer 130 using the same material as the semiconductor layer 140. In this case, the conductive layer 210 can be formed by processing a film that is formed simultaneously with the semiconductor layer 140. Therefore, the conductive layer 210 contains the same elements as the semiconductor layer 140. It may have a crystal structure similar to or different from that of the semiconductor layer 140. The film formed at the same time as the silicon dioxide is made conductive by having impurities or oxygen deficiencies. This allows the conductive layer 210 to be formed. Typical examples of impurities contained in the conductive layer 210 include: These include the noble gases, hydrogen, boron, nitrogen, fluorine, aluminum, or phosphorus. Representative examples include helium, neon, argon, krypton, and xenon. Although the conductive layer 210 has conductivity, one embodiment of the present invention is not limited to this. In some cases or circumstances, the conductive layer 210 may not necessarily be conductive. In other words, the conductive layer 210 does not have to have the same properties as the semiconductor layer 140. It may be possible.

[0072] As described above, the semiconductor layer 140 and the conductive layer 210 are both formed on the insulating layer 130. The impurity concentration is different. Specifically, the impurity concentration of the conductive layer 210 is different from that of the semiconductor layer 140. For example, in the semiconductor layer 140, the hydrogen concentration obtained by secondary ion mass spectrometry is Degrees are 5 x 10 19 atoms / cm 3 Less than or equal to 5 x 10 18 atoms / cm 3 or less, more preferably 1 × 10 18 atoms / cm 3 Less than or equal to 5x1, more preferably 0 17 atoms / cm 3Below 1×10, most preferably 16 atoms / cm 3 Below On the other hand, the hydrogen concentration in the conductive layer 210 obtained by secondary ion mass spectrometry is 8×10 19 atoms / cm 3 or more, preferably 1 × 10 20 atoms / cm 3 End , more preferably 5 × 10 20 atoms / cm 3 The above is the case. In comparison, the hydrogen concentration in the conductive layer 210 is double or even ten times higher.

[0073] By setting the hydrogen concentration in the semiconductor layer 140 within the above range, the carriers in the semiconductor layer 140 It is possible to suppress the production of certain electrons.

[0074] The oxide semiconductor film formed simultaneously with the semiconductor layer 140 is exposed to plasma. The semiconductor film can be damaged and oxygen vacancies can be formed. For example, an oxide semiconductor film When a film is formed on the surface by plasma CVD or sputtering, the oxide semiconductor film is The insulating layer 170 is exposed to the plasma to generate oxygen vacancies. In the etching treatment, oxygen vacancies are generated when the oxide semiconductor film is exposed to plasma. Alternatively, the oxide semiconductor film may be formed by using a mixed gas of oxygen and hydrogen, hydrogen, a rare gas, or ammonia. When exposed to plasma such as nitrogen, oxygen vacancies are generated in the oxide semiconductor film. By adding a pure substance, oxygen vacancies are formed and the impurity is added to the oxide semiconductor film. The impurity doping method can be ion doping, ion implantation, plasma In the case of plasma treatment, the plasma is generated in a gas atmosphere containing the impurities to be added. By generating a plasma and performing plasma treatment, the accelerated impurity ions are accelerated into the oxide semiconductor. By colliding with the conductive film, oxygen vacancies can be formed in the oxide semiconductor film.

[0075] An impurity, for example, hydrogen, is added to an oxide semiconductor film in which oxygen vacancies are formed by adding an impurity element. When oxygen is contained, hydrogen enters the oxygen vacancy site and a donor level is formed near the conduction band. As a result, the oxide semiconductor film becomes highly conductive and becomes a conductor. The semiconductor layer 140 can be called an oxide conductor film. The conductive layer 210 is formed of an oxide conductive film. It can be said that the conductive layer 210 is formed using an oxide semiconductor film with high conductivity. It can also be said that it is formed from a high metal oxide film.

[0076] The insulating layer 180 preferably contains hydrogen. Therefore, when the insulating layer 180 contains hydrogen, the hydrogen in the insulating layer 180 is absorbed by the semiconductor layer 14 As a result, the semiconductor layer 1 can be diffused into the oxide semiconductor film formed at the same time as the semiconductor layer 1. Impurities can be added to the oxide semiconductor film formed at the same time as the oxide semiconductor film 40 .

[0077] Furthermore, the insulating layer 170 is an oxide insulating layer containing more oxygen than the stoichiometric composition. Preferably, the insulating layer 180 is formed of an insulating film containing hydrogen. The oxygen contained in layer 170 migrates to semiconductor layer 140 of transistor 60, thereby forming a semiconductor The amount of oxygen vacancies in the layer 140 can be reduced, and the fluctuation in the electrical characteristics of the transistor 60 can be reduced. At the same time, hydrogen contained in the insulating layer 180 moves to the conductive layer 210, increasing the conductivity of the conductive layer 210. It can be done.

[0078] By the above method, the conductive layer 210 is formed simultaneously with the semiconductor layer 140, and is made conductive after the formation. By adopting this configuration, it is possible to reduce manufacturing costs.

[0079] In general, an oxide semiconductor film is transparent to visible light due to its large energy gap. On the other hand, the oxide conductor film is an oxide semiconductor having a donor level near the conduction band. Therefore, the influence of absorption due to the donor level is small, and the oxide It has the same level of light transmittance as a semiconductor film.

[0080] As described above, the conductive layer 190 and the conductive layer 210 have a light-transmitting property. The capacitor element can be made to be light-transmitting as a whole.

[0081] With the above configuration, the aperture ratio of the pixels in the display region can be improved. The improved aperture ratio allows the display to maintain the same brightness even when the backlight is dimmed. This allows for lower power consumption.

[0082] The conductive layer 190 functions as a pixel electrode of the liquid crystal layer 200. The conductive film is formed by using a conductive film that transmits light. For example, the metal may be one selected from indium (In), zinc (Zn), and tin (Sn). Alternatively, the conductive layer 210 can be used as a pixel electrode. The conductive layer 190 is a conductive film that is transparent to visible light or a conductive film that is reflective to visible light. The conductive layer 190 is formed using a conductive film that is transparent to visible light. A transmission type display device can be manufactured by forming the conductive layer 1. 90 is formed using a conductive film that is reflective to visible light, Transmissive displays can be fabricated.

[0083] As shown in the cross-sectional view of FIG. 4(A), the conductive layer 160 may be connected to the conductive layer 210. good.

[0084] Liquid crystal element The liquid crystal layer 200 is sandwiched between the conductive layer 190 and a conductive layer 310 provided on the substrate 300. When the conductive layer 190 and the conductive layer 310 apply an electric field to the liquid crystal element 330, Note that the liquid crystal element 330 may be formed without providing the conductive layer 310.

[0085] The display device can be driven in various modes, such as TN mode, STN mode, VA mode, ASM, etc. (Axially Symmetric Aligned Micro-cell) mode OCB (Optically Compensated Birefringenc) e) mode, FLC (Ferroelectric Liquid Crystal) mode AFLC (AntiFerroelectric Liquid Crystal) ) mode, MVA mode, PVA (Patterned Vertical Align ment) mode, IPS mode, FFS mode, or TBA (Transverse A bend alignment mode may also be used. In addition to the above mentioned driving method, ECB (Electrically Controlled Bias Circuit) LED Birefringence mode, PDLC (Polymer Dispersion rsed Liquid Crystal) mode, PNLC (Polymer Net There are various modes, such as the "Work" mode (Liquid Crystal mode) and the "Guest Host" mode. However, the present invention is not limited to this, and various liquid crystal elements and their driving methods can be used. Cut.

[0086] In addition, the liquid crystal element 330 is formed by using a liquid crystal composition containing a liquid crystal exhibiting a nematic phase and a chiral agent. In this case, a cholesteric phase or a blue phase (Blue Ph The liquid crystal that shows the blue phase has a short response time of 1 msec or less, and Since the liquid crystal display is substantially isotropic, no alignment treatment is required and the viewing angle dependency is small.

[0087] The substrate 300 has a conductive layer 310, and the liquid crystal layer 200 is sandwiched between the conductive layer 310 and the conductive layer 190. The liquid crystal element 330 can be formed by the electric field from the conductive layer 190 and the conductive layer 310. This makes it possible to control the orientation of the liquid crystal molecules in the liquid crystal layer 200 .

[0088] Circuit 30 Next, the circuit 30 of the display device will be described.

[0089] The circuit 30 includes a transistor 1060 and a capacitor 1070 .

[0090] "Transistor 1060" The transistor 1060 includes an insulating layer 1110, a conductive layer 1120, an insulating layer 1130, and a semiconductor layer. Conductor layer 1140, conductive layer 1150, conductive layer 1160, insulating layer 1170, and insulating layer 1171. The conductive layer 1120 functions as a gate electrode. The semiconductor layer 1140 has a function as a gate insulating film. The conductive layer 1150 functions as a semiconductor layer that forms a source electrode or a drain electrode. The conductive layer 1160 functions as the other of the source electrode and the drain electrode. The conductive layer 1160 is connected to the conductive layer 1190. The insulating layer 1170 The insulating layer 1180 can be used to protect the channel portion. It can be used to prevent this.

[0091] <Capacitor element 1070> The capacitor 1070 includes a conductive layer 1190, an insulating layer 1180, and a conductive layer 1210. The conductive layer 1190 functions as one electrode of the capacitor 1070. The conductive layer 1190 and the conductive layer 210 function as the other electrode of the capacitor 1070. An insulating layer 1180 is provided between the conductive layer 1210 and the transistor. It is connected to the printer 1060.

[0092] Note that the conductive layer 1160 is connected to the conductive layer 1210 as shown in the cross-sectional view of FIG. 4(B). This may also be done.

[0093] The transistor 1060 can be formed in the same process as the transistor 60. All the elements that make up this transistor can be made of the same material. The edge layer 110 and the insulating layer 1110 can be formed in the same process.

[0094] The capacitor element 1070 can be formed in the same process as the capacitor element 70. The elements constituting the device can all be made of the same material. For example, the conductive layer 210 The conductive layer 1210 and the conductive layer 1211 can be formed in the same process. The conductive layer 1210 and the semiconductor layer 1140 can be formed of the same material. 1210 is formed by processing a film formed at the same time as the semiconductor layer 1140. The conductive layer 1210 contains the same elements as the semiconductor layer 1140. However, The film formed at the same time as 140 is made conductive by having impurities or oxygen deficiencies. The conductive layer 1210 can be formed by applying a conductive material to the conductive layer 1210. However, one embodiment of the present invention is not limited to this. Alternatively, depending on the situation, the conductive layer 1210 does not necessarily have to be made conductive. Therefore, the conductive layer 1210 may have similar properties to the semiconductor layer 1140 .

[0095] For example, the conductive layer 1190 and the conductive layer 1210 have a light-transmitting property. The element 1070 can be a light-transmitting capacitor element as a whole.

[0096] 《Adhesive layer 400》 The adhesive layer 400 has the function of bonding the substrate 100 and the substrate 300 together.

[0097] The adhesive layer 400 may be made of an inorganic material, an organic material, or a composite material of an inorganic material and an organic material. can be done.

[0098] For example, light-curing adhesives, reaction-curing adhesives, heat-curing adhesives, and / or anaerobic adhesives. Organic materials such as adhesives can be used for the adhesive layer 400. They can be used singly or in combination.

[0099] The photocurable adhesive is an adhesive that is cured by, for example, ultraviolet light, electron beam, visible light, infrared light, etc. say.

[0100] Specifically, epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyrate) Adhesives containing EVA (ethylene vinyl acetate) resin, silica, etc. are used as adhesive layers. Can be used for 400.

[0101] In particular, when using a light-curing adhesive, the material hardens quickly, shortening the work time. In addition, since curing begins when exposed to light, the adhesive does not change intentionally due to environmental factors. It is possible to prevent the adhesive from hardening without being applied. The working environment can be easily controlled. As a result, the process can be shortened by using a light-curing adhesive. This allows for inexpensive processing.

[0102] In FIG. 2B, when a photo-curing adhesive is used as the adhesive layer 400, the adhesive layer 4 If a material that absorbs or reflects light is used in the area in contact with the adhesive layer 400, However, there is a possibility that sufficient light will not be irradiated to the surface, resulting in insufficient adhesion. Meanwhile, in one embodiment of the present invention, the capacitor 1070 in FIG. 2B has a conductive layer 11 Since both the insulating layer 90 and the conductive layer 1210 are made of a light-transmitting material, the capacitance element 1 As a result, the adhesive layer 400 can be sufficiently hardened. This allows a display device to be manufactured inexpensively and with high productivity. This also makes it possible to narrow the frame (shortening the distance from the edge of the substrate to the display area). In this case, at least a part of the capacitor element 1070 does not overlap with the adhesive layer 400. Even if the capacitor element 1070 does not overlap the adhesive layer 400, the capacitor element 1070 may be formed on the adhesive layer 400. If the capacitance element 1070 is located near 0, the light is irradiated onto the adhesive layer 400 via the capacitance element 1070. It is possible.

[0103] The transistor described in this embodiment includes an oxide semiconductor. However, one embodiment of the present invention is not limited to this. Depending on the situation, one embodiment of the present invention may be a transistor using a semiconductor material other than an oxide semiconductor. A star may also be used.

[0104] For example, a transistor using a group 14 element, a compound semiconductor, or an oxide semiconductor in the semiconductor layer Specifically, semiconductors containing silicon, semiconductors containing gallium arsenide, Or organic semiconductors, semiconductors containing silicon carbide, semiconductors containing germanium, silicon germanium Transistors using semiconductors containing rhenium, carbon nanotubes, etc. can be applied. .

[0105] For example, single crystal silicon, polysilicon, or amorphous silicon may be used for the transistor. This can be applied to semiconductor layers.

[0106] In this embodiment, when the conductive layer 210 is formed of the same material as the semiconductor layer 140, However, one aspect of the present invention is not limited to these. Alternatively, depending on the situation, as an embodiment of the present invention, the conductive layer 210 and the semiconductor layer 1 40 may have different materials. The same can be said for the semiconductor layer 1140.

[0107] In this embodiment, the conductive layer 1210 is formed using the same material as the semiconductor layer 1140. However, one aspect of the present invention is not limited to these. In some cases, or depending on the circumstances, one aspect of the present invention is to The layers 1140 may be made of different materials.

[0108] In this embodiment, the capacitor element 1070 and the capacitor element 70 are formed in the same process. The elements constituting the two capacitance elements are all made of the same material. However, one aspect of the present invention is not limited to this. In accordance with this, as one embodiment of the present invention, the capacitor 1070 and the capacitor 70 are at least The parts may be formed in different processes. Alternatively, depending on the situation, as one embodiment of the present invention, the capacitor 1070 and the capacitor 70 may be At least some may have different materials.

[0109] Note that the structures and methods described in this embodiment may be different from the structures and methods described in other embodiments. can be used in appropriate combination.

[0110] (Embodiment 2) In this embodiment, a modification of the display device described in the first embodiment will be described.

[0111] 5 and 6 show top views of circuit 30.

[0112] In the capacitor 1070 of the circuit 30, the conductive layer 1190 having a function as an electrode is transparent. In order to improve the optical properties, various shapes as shown in FIGS. 5(A) to 5(D) may be used. good.

[0113] Alternatively, in the capacitor 1070 of the circuit 30, the conductive layer 1210 functioning as an electrode may be In order to improve the light transmittance, various shapes as shown in Fig. 6(A) and Fig. 6(B) may be used. For example, the shape of the opening 1270 may be square or round. good.

[0114] Alternatively, in the circuit 30, the light transmittance is not limited to a capacitor element, and may be any of the elements shown in FIG. ), as shown in FIG. 6(D), the shapes of the conductive layer 1120, the conductive layer 1150, etc. may be changed. For example, openings 1410 may be provided in the conductive layer 1120, the conductive layer 1150, etc. An opening 1420 is provided in the conductive layer 1120, the conductive layer 1150, etc., and they are connected by the conductive layer 1190. In this way, the openings 1270, 1410, and 1420 may be formed in the adhesive layer 40. 0 or in the vicinity of the adhesive layer 400, can be more easily irradiated.

[0115] Alternatively, in the above structure, a light-transmitting A material made of a material other than copper or a metal material may be used.

[0116] By adopting the above-mentioned shape, the curing property of the photo-curable adhesive in the circuit 30 is improved, and the manufacturing cost is low. The display device can be produced with high productivity.

[0117] Note that the structures and methods described in this embodiment may be different from the structures and methods described in other embodiments. can be used in appropriate combination.

[0118] (Embodiment 3) In this embodiment, another embodiment of the display device 10 according to one aspect of the present invention will be described with reference to FIG. I will explain.

[0119] 7A is a top view of the display device 10, FIG. 7B is a top view of the circuit 30, and FIG. 7C is a top view of the circuit 30 is a cross-sectional view taken along the dashed line BB′ in the top view of the device.

[0120] The display device 10 shown in FIG. 7 has the same structure as the display device 10 shown in FIGS. 1 and 2 and the capacitive element. The only difference is the composition, and the other components are the same. Therefore, the description of the transistors, etc. will be omitted. .

[0121] <Capacitor element 1070> The capacitor 1070 includes a conductive layer 1190, an insulating layer 1180, and a conductive layer 1210. The conductive layer 1190 functions as one electrode of the capacitor 1070. The conductive layer 1190 and the conductive layer 210 function as the other electrode of the capacitor 1070. An insulating layer 1180 is provided between the conductive layer 1210 and the transistor. It is connected to the printer 1060.

[0122] <Capacitor element 1080> The capacitor 1080 includes a conductive layer 1220, an insulating layer 1130, and a conductive layer 1210. The conductive layer 1220 functions as one electrode of the capacitor 1080. The conductive layer 210 functions as the other electrode of the capacitor 1080. An insulating layer 1130 is provided between the conductive layer 1210 and the insulating layer 1130 .

[0123] <Relationship between Capacitor 1070 and Capacitor 1080> The capacitor element 1070 and the capacitor element 1080 can be disposed in an overlapping manner. The conductive film 1060 functions as an electrode of the capacitor 1070 and an electrode of the capacitor 1080. The conductive layer 1190 and the conductive layer 1220 are electrically connected and have the same potential. can.

[0124] The conductive layer 1210 is formed simultaneously with the semiconductor layer 1140, and is made conductive after the formation. This configuration makes it possible to reduce manufacturing costs.

[0125] The conductive layer 1190, the conductive layer 1210, and the conductive layer 1220 each have a light-transmitting property. Therefore, the capacitors 1070 and 1080 are made of light-transmitting capacitors. The conductive layer 1220 can be formed of the same material as the conductive layer 1120. It may be formed in a process.

[0126] In FIG. 7C, when a photo-curing adhesive is used as the adhesive layer 400, the adhesive layer 400 and If a material that absorbs or reflects light is used in the contact area, the adhesive layer 400 may not be sufficiently However, the adhesiveness of the present invention is insufficient because the light cannot be irradiated sufficiently. In one embodiment, in FIG. 7C, the capacitor 1070 includes a conductive layer 1190 and a conductive layer 1191. Since both the capacitor element 1070 and the capacitor element 210 are made of a light-transmitting material, light can pass through the capacitor element 1070. The capacitor 1080 has a structure in which a conductive layer 1210 and a conductive layer 12 20. Both are made of translucent materials, allowing light to pass through. As a result, the adhesive layer 400 can be sufficiently hardened, and the display device can be manufactured inexpensively and with high productivity. It is possible to create a device.

[0127] By adopting the above structure, the photo-curing property of the adhesive material is improved, and the display device can be manufactured at low cost with high productivity. In addition, when a sufficient area for the capacitor element cannot be secured due to the circuit configuration, Therefore, the capacitance can be increased without increasing the area of ​​the capacitive element.

[0128] The transistor described in this embodiment includes an oxide semiconductor. However, one embodiment of the present invention is not limited to this. Depending on the situation, one embodiment of the present invention may be a transistor using a semiconductor material other than an oxide semiconductor. A star may also be used.

[0129] For example, a transistor using a group 14 element, a compound semiconductor, or an oxide semiconductor in the semiconductor layer Specifically, semiconductors containing silicon, semiconductors containing gallium arsenide, Alternatively, a transistor using an organic semiconductor or the like can be applied.

[0130] For example, single crystal silicon, polysilicon, or amorphous silicon may be used for the transistor. This can be applied to semiconductor layers.

[0131] Note that the electrodes of the capacitor are formed using a light-transmitting conductive layer, but are not limited to this. It can also have materials etc.

[0132] Although the capacitor 1070 in the circuit 30 is shown as an example, the capacitor 70 in the circuit 20 The above structure may be applied. This allows the area of ​​the capacitance element to be reduced, and the pixel surface area This makes it possible to reduce the area and increase the pixel density, thereby enabling the production of high-definition display devices. In addition, the above structure may be applied to a capacitor included in the circuit 40.

[0133] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. .

[0134] (Fourth embodiment) In this embodiment mode, the display devices described in Embodiment Modes 1 to 3 will be described in detail with reference to FIG. explain.

[0135] 8A to 8D are examples of top views and cross-sectional views of the display device 10. In A), a circuit 20 (display area), a circuit 30 (drive circuit gate driver), a circuit 40 (drive circuit source driver), and flexible printed circuit (FPC) 9 shows a portion of a typical configuration having a printed circuit) 900, each of which FIG. 8B shows an example of a top view of a pixel circuit included in the circuit 20. 1 shows an example of a top view of a part of the circuit 30. FIG.

[0136] FIG. 8(D) is a cross-sectional view taken along the dashed line CC' in FIG. 8(A), and FIG. 8(B) is a cross-sectional view taken along the dashed line BB. 8(C) shows a cross-sectional view taken along the dashed line A-A' in FIG. 8(C). In the region, a substrate 100, a display element (for example, a liquid crystal element 330 including a liquid crystal layer 200), and a substrate The substrate 1 is laminated in the above order. The substrate 300 is bonded to the substrate 300 by an adhesive layer 400. In the figure, the touch sensor 500 is provided on the plate 300. It is also possible to adopt a configuration in which this is not provided.

[0137] <<Board 100, 300>> There is no particular restriction on the material of the substrates 100 and 300, but at least they should be able to withstand the subsequent heat treatment. It is necessary for the material to have a heat resistance sufficient to withstand the heat. It is desirable for the material to have high light transmittance.

[0138] The substrate 100 may be made of an organic material, an inorganic material, or a composite material such as an organic material and an inorganic material. For example, inorganic materials such as glass, ceramics, and metals can be used for the substrate 100. can be done.

[0139] Specifically, alkali-free glass, soda-lime glass, potash glass, or crystal glass For example, an inorganic oxide film, an inorganic nitride film, or the like can be used for the substrate 100. An inorganic oxynitride film or the like can be used for the substrate 100. For example, silicon oxide, nitride Silicon, silicon oxynitride, alumina, etc. can be used for the substrate 100. The substrate 100 may be made of stainless steel or aluminum, for example.

[0140] For example, organic materials such as resin, resin film, or plastic may be used for the substrate 100. Specifically, polyester, polyolefin, polyamide, polyimide, poly A resin film or plate such as a carbonate or acrylic resin is used as the substrate 100. It is possible.

[0141] For example, a metal plate, a thin glass plate, or a film of an inorganic material is laminated to a resin film or the like. A composite material such as a fibrous or particulate metal, a glass, or the like can be used for the substrate 100. A composite material in which glass or inorganic material is dispersed in a resin film is used for the substrate 100. For example, a fibrous or particulate resin or organic material can be dispersed in an inorganic material. Composite materials may be used for the substrate 100 .

[0142] Additionally, a single layer material or a multi-layer laminated material can be used for the substrate 100. For example, a material that is laminated with a base material and an insulating film that prevents the diffusion of impurities contained in the base material is called a substrate. Specifically, it can be used to prevent the diffusion of glass and impurities contained in the glass. One or more layers selected from a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, etc. A material in which several films are laminated can be applied to the substrate 100. Alternatively, a material made of a resin and an impermeable material that can penetrate the resin can be applied. A silicon oxide film, a silicon nitride film, a silicon oxynitride film, or the like is laminated to prevent the diffusion of impurities. The resulting material can be applied to the substrate 100 .

[0143] The substrates applicable to the substrate 100 described above can also be applied to the substrate 300.

[0144] Insulating layers 110 and 1100 The insulating layers 110 and 1110 functioning as base films are made of silicon oxide, oxynitride, or the like. Silicon, silicon nitride, silicon oxide nitride, gallium oxide, hafnium oxide, gallium oxide It is formed using thorium, aluminum oxide, aluminum oxynitride, etc. The layer 110 may be made of silicon nitride, gallium oxide, hafnium oxide, yttrium oxide, or oxide. By using aluminum chloride or the like, impurities, typically alkali metals, water, etc., are removed from the substrate 100. This can suppress the diffusion of hydrogen and the like into the oxide semiconductor layer 240. The insulating layer 1110 is formed on the insulating layer 100. Also, the insulating layer 110 may not be formed. , and is made of a film having the same composition as the insulating layer 110 .

[0145] Conductive layers 120, 1120 The conductive layers 120 and 1120 functioning as gate electrodes are made of aluminum, chromium, copper, , tantalum, titanium, molybdenum, nickel, iron, cobalt, and tungsten Metal elements, alloys containing the above-mentioned metal elements, or combinations of the above-mentioned metal elements It is formed using an alloy containing manganese, zirconium, or a combination thereof. The conductive layer 120 may be formed using a metal element selected from the group consisting of: For example, a single layer structure of an aluminum film containing silicon may be used. , a single layer structure of copper film containing manganese, a two-layer structure of titanium film laminated on aluminum film, Two-layer structure in which a titanium film is laminated on a titanium nitride film, and a tungsten film is laminated on a titanium nitride film. a two-layer structure in which a tungsten film is laminated on a tantalum nitride film or a tungsten nitride film; Layer structure, two-layer structure in which a copper film is laminated on a copper film containing manganese, a titanium film and a titanium film on the titanium film A three-layer structure is formed by laminating an aluminum film on the surface and then forming a titanium film on top of that. There are three-layer structures in which a copper film containing manganese is formed on top of a copper film containing manganese. In addition, titanium, tantalum, tungsten, molybdenum, chromium, nickel, An alloy film or nitride film made by combining one or more of the following: chromium, chromium, and scandium The conductive layer 1120 may be a film having the same composition as the conductive layer 120. .

[0146] Insulating layers 130 and 1130 The insulating layers 130 and 1130 also function as gate insulating films. is, for example, aluminum oxide, magnesium oxide, silicon oxide, silicon oxynitride, Silicon oxynitride, silicon nitride, gallium oxide, germanium oxide, yttrium oxide , zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide and tantalum oxide The insulating layer 130 may be a laminate of the above materials. The insulating layer 130 may contain lanthanum (La), nitrogen, zirconium (Zr), etc. The insulating layer 1130 is formed at the same time as the insulating layer 13. A film of the same composition as in Example 0 is used.

[0147] <Oxide semiconductor layers 240, 1240> The oxide semiconductor layers 240 and 1240 are formed of a metal oxide containing at least In or Zn. Typically, In-Ga oxide, In-Zn oxide, In-M-Zn oxide (M The oxide semiconductor is made of Al, Ga, Y, Zr, La, Ce, or Nd. The oxide semiconductor layer 1240 is formed at the same time as the oxide semiconductor layer 240 and is made of a film having the same composition as the oxide semiconductor layer 240. do.

[0148] When the oxide semiconductor layers 240 and 1240 are made of In-M-Zn oxide, In When the sum of In and M is 100 atomic %, the atomic ratio of In to M is preferably In is higher than 25 atomic % and M is less than 75 atomic %, and more preferably I n is greater than 34 atomic % and M is less than 66 atomic %.

[0149] The oxide semiconductor layers 240 and 1240 have an energy gap of 2 eV or more, preferably 2. The energy gap is 5 eV or more, and more preferably 3 eV or more. By using an oxide semiconductor, the off-state current of the transistor 60 can be reduced.

[0150] The thickness of the oxide semiconductor layer 240, 1240 is 3 nm or more and 200 nm or less, preferably 3 nm or less. The thickness is preferably from m to 100 nm, more preferably from 3 nm to 50 nm.

[0151] The oxide semiconductor layers 240 and 1240 are made of In-M-Zn oxide (wherein M is Al, Ga, Y, Zr, When formed using In-Zn oxide, the In-M-Zn oxide is formed using In, Ce, or Nd. The atomic ratio of the metal elements in the sputtering target used for this purpose satisfies In≧M, Zn≧M. It is preferable that the atomic ratio of the metal elements in such a sputtering target is , In:M:Zn=1:1:1, In:M:Zn=1:1:1.2, In:M:Zn=3 In:M:Zn=4:1:4.1 is preferable. The atomic ratios of the metal elements in the layers 240 and 1240 are determined by the above sputtering method as an error. The atomic ratio of the metal elements contained in the target can vary by ±40%. A target containing In-Ga-Zn oxide, preferably a polycrystalline target containing In-Ga-Zn oxide By using a crystal target, it is possible to achieve CAAC-OS (C Axis Alignment) d Crystalline Oxide Semiconductor) film and microcrystals It is possible to form a crystalline oxide semiconductor film.

[0152] The hydrogen contained in the oxide semiconductor reacts with the oxygen that bonds with the metal atoms to form water, and the acid Oxygen vacancies are formed in the lattice where oxygen has been desorbed (or in the part where oxygen has been desorbed). When hydrogen enters, electrons, which act as carriers, may be generated. By bonding with oxygen, which bonds with a metal atom, electrons that act as carriers may be generated. Therefore, a transistor using an oxide semiconductor containing hydrogen has normally-on characteristics. Easy to use.

[0153] Therefore, in the oxide semiconductor layers 240 and 1240, oxygen vacancies and hydrogen are reduced as much as possible. Specifically, in the oxide semiconductor layers 240 and 1240, the secondary Secondary Ion Mass Spectrometry (SIMS) The hydrogen concentration obtained by the hydrogen concentration meter is 5×10 19 atoms / cm 3 Below, more preferred Preferably 1 x 10 19 atoms / cm 3 Below, 5 x 10 18 atoms / cm 3 below, Preferably 1 x 10 18 atoms / cm 3 Less than or equal to 5 × 10 17 atom s / cm 3 or less, more preferably 1 × 10 16 atoms / cm 3 The following is the result. As a result, the transistor 60 has electrical characteristics in which the threshold voltage is positive (normally-off characteristics). Also called. )

[0154] In addition, in the oxide semiconductor layers 240 and 1240, silicon, which is one of the group 14 elements, When carbon is contained, oxygen vacancies increase in the oxide semiconductor layers 240 and 1240, and the oxide semiconductor layers 240 and 1240 become n-type. As a result, the concentrations of silicon and carbon in the oxide semiconductor layers 240 and 1240 (concentration obtained by secondary ion mass spectrometry) is 2 x 10 18 atoms / cm 3 below , preferably 2 x 10 17 atoms / cm 3 As a result, transistor 60 has electrical characteristics in which the threshold voltage is positive (also called normally-off characteristics).

[0155] In addition, in the oxide semiconductor layers 240 and 1240, the The concentration of alkali metals or alkaline earth metals is 1×10 18 atoms / cm 3 below, Preferably 2 x 10 16 atoms / cm 3 The following are alkali metals and alkaline earth metals: When a metal bonds with an oxide semiconductor, it can generate carriers, which can cause the transistor to turn off. Therefore, the alkali metal oxide semiconductor layers 240 and 1240 are It is preferable to reduce the concentration of alkali metals or alkaline earth metals. The transistor 60 has an electrical characteristic in which the threshold voltage is positive (also called a normally-off characteristic). do.

[0156] Furthermore, when nitrogen is contained in the oxide semiconductor layers 240 and 1240, electrons serving as carriers This increases the carrier density and makes the transistor more likely to become n-type. Therefore, nitrogen is easily formed in the oxide semiconductor layers 240 and 1240. It is preferable that the nitrogen content is reduced as much as possible, for example, by secondary ion mass spectrometry. The concentration is 5 x 10 18 atoms / cm 3 It is preferable to do the following:

[0157] By reducing impurities in the oxide semiconductor layers 240 and 1240, Therefore, the carrier density of the oxide semiconductor layer 240 can be reduced. 240 has a carrier density of 1×10 15 pieces / cm 3 Less than 1 × 10 13 pcs / c m 3 Less than 8 × 10, more preferably 11 pieces / cm 3 less than 1×10 11 pieces / cm 3 less than 1 x 10 10 pieces / cm 3 Less than 1 x 10 -9 pieces / cm 3 That's all.

[0158] The oxide semiconductor layers 240 and 1240 are oxide semiconductors having different atomic ratios of metal elements. For example, as shown in FIG. 9(A), an oxide film may be formed on an insulating layer 130. Alternatively, the compound semiconductor layers 240 and 241 may be stacked in this order. Alternatively, oxide semiconductor layers 242, 240, and 241 may be stacked in this order on the insulating layer 130. The compound semiconductor layers 241 and 242 have a different atomic ratio of metal elements from that of the oxide semiconductor layer 240 . The oxide semiconductor layer 1240 may also have a similar structure.

[0159] The oxide semiconductor layer 240 is made of an oxide semiconductor having a low impurity concentration and a low density of defect states. By using the above-mentioned method, a transistor having even better electrical characteristics can be manufactured. In this case, the low impurity concentration and low defect level density (low oxygen vacancies) are called high purity intrinsic or High purity intrinsic or substantially high purity intrinsic oxide semiconductors The body may be able to have a low carrier density due to the scarcity of carrier sources. Therefore, a channel region is formed in the oxide semiconductor layer 240 formed using the oxide semiconductor. The transistors that are formed have electrical characteristics in which the threshold voltage is positive (normally off characteristics). In addition, oxide semiconductors that are high-purity intrinsic or substantially high-purity intrinsic are prone to The defect level density is low in the silicon dioxide, so the trap level density may also be low. The oxide semiconductor layer 240 is formed using an intrinsic or substantially highly pure intrinsic oxide semiconductor. The transistor has a significantly small off-state current and a low voltage between the source and drain electrodes ( In the drain voltage range of 1V to 10V, the off-state current is Below the measurement limit of the isa, i.e., 1 × 10 -13 A characteristic of less than A can be obtained. Therefore, the transistor in which the channel region is formed in the oxide semiconductor layer 240 has the following electrical characteristics: The fluctuation in the resistance may be small, resulting in a highly reliable transistor.

[0160] In the case of a transistor using an oxide semiconductor, the oxide semiconductor layer 240 is formed by sputtering. This makes it possible to use the display device as a large-area display device.

[0161] Note that instead of the oxide semiconductor layer 240, a layer formed of silicon or silicon germanium may be used. A semiconductor layer made of silicon or silicon germanium may be formed. The body layer may have an amorphous structure, a polycrystalline structure, or a single crystal structure, as appropriate.

[0162] Conductive layers 150, 160, 1150, 1160, and 2150 The pair of conductive layers 150 and 160 function as a source electrode and a drain electrode. The pairs of conductive layers 150, 160, 1150, 1160, and conductive layer 2150 are made of aluminum. Aluminum, Chromium, Copper, Tantalum, Titanium, Molybdenum, Nickel, Iron, Cobalt, Tan or an alloy containing the above-mentioned metal elements, or It is made of an alloy of metal elements. The conductive layer 1 may be formed using one or more metal elements selected from the above. 50, 160, 1150, 1160, 2150 are available in single layer structure and laminated structure of two or more layers. For example, a single layer structure of an aluminum film containing silicon, a copper film containing manganese, Single layer structure, double layer structure with titanium film laminated on aluminum film, titanium film on titanium nitride film a two-layer structure in which a tungsten film is laminated on a titanium nitride film; Two-layer structure consisting of a tungsten film on a tungsten nitride film or a manganese-containing film Two-layer structure with copper film stacked on top of copper film, titanium film, and aluminum film stacked on top of the titanium film A three-layer structure is formed by forming a titanium film on top of that, and a copper film is laminated on top of a copper film containing manganese. There are three-layer structures, such as a copper film containing manganese on top of the copper film. Titanium, tantalum, tungsten, molybdenum, chromium, neodymium, scandium Alternatively, an alloy film or a nitride film made by combining one or more selected from the above may be used. The conductive layers 1150, 1160 and the conductive layer 2150 are made of the same composition as the conductive layers 150, 160. It consists of a membrane.

[0163] Insulation layers 170, 1170, 2170 The insulating layer 170 has a function of protecting the channel region of the transistor. , silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, gas oxide gallium, gallium oxide nitride, yttrium oxide, yttrium oxide nitride, hafnium oxide oxide insulating films such as hafnium oxide nitride; nitride insulating films such as silicon nitride and aluminum nitride; The insulating layer 170 may be a single layer or a laminated layer. In addition, the insulating layer 1170 and the insulating layer 2170 are made of a film having the same composition as the insulating layer 170. are.

[0164] The insulating layer 170 is an oxide insulating layer containing more oxygen than the oxygen required for the stoichiometric composition. It is preferable to form the film by using a material containing more oxygen than the oxygen required for the stoichiometric composition. When heated, the oxide insulating film containing oxygen is partially desorbed. Oxide insulating films containing more oxygen than TDS (Thermal Desorption Spectroscopy analysis shows that the film surface temperature is between 100°C and 700°C. , or the amount of oxygen atoms released in the range of 100°C to 500°C is 1.0 × 10 18 atoms / cm 3 or more, preferably 3.0 × 10 20 atoms / cm 3 Acid that is more than The heat treatment removes oxygen contained in the insulating layer 170 from the oxide semiconductor layer 240. , and oxygen vacancies in the oxide semiconductor layer 240 can be reduced. is.

[0165] Insulation layer 180, 1180, 2180 The insulating layer 180 is provided with an insulating film having a blocking effect against oxygen, hydrogen, water, etc. The diffusion of oxygen from the oxide semiconductor layer 240 to the outside and the diffusion of oxygen from the outside to the oxide semiconductor layer 240 For example, aluminum oxide, magnesium oxide, etc. can be used to prevent the intrusion of hydrogen, water, etc. Silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, gallium oxide , germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide An insulating film containing one or more of tantalum oxide, hafnium oxide, and tantalum oxide can be used. The insulating layer 180 may also be a laminate of the above materials. It may contain impurities such as La, nitrogen, and zirconium (Zr). The edge layer 1180 and the insulating layer 2180 are made of films of the same composition as 180 .

[0166] Conductive layers 190, 1190, and 2190 The conductive layer 190 is formed using a conductive film that transmits visible light. Examples of the conductive film having transparency include indium (In), zinc (Zn), and tin (Sn ) It is preferable to use a material containing one selected from the group consisting of: The conductive film is typically made of indium tin oxide or indium containing tungsten oxide. oxide, indium zinc oxide with tungsten oxide, indium oxide with titanium oxide oxides, indium tin oxides containing titanium oxide, indium zinc oxides, silicon oxides A conductive oxide such as indium tin oxide can be used. , 2190 are made of a film having the same composition as the conductive layer 190 .

[0167] Conductive layer 250, 1250 The conductive layer 250 is formed on the insulating layer 130, similar to the oxide semiconductor layer 240. The conductive layer 1250 is formed on the insulating layer 1130, similar to the oxide semiconductor layer 1240. Conductive layer 1250 can be formed at the same time as conductive layer 250 and from the same material.

[0168] In addition, the transistor 60 may be a transistor including an oxide semiconductor layer 240. The conductive layer 250 can be formed on the insulating layer 130 using the same material as the oxide semiconductor layer 240. In this case, the conductive layer 250 can be formed by processing a film formed simultaneously with the oxide semiconductor layer 240. Therefore, the conductive layer 250 contains the same elements as the oxide semiconductor layer 240. The oxide semiconductor layer 240 may have a crystal structure similar to or different from that of the oxide semiconductor layer 240. However, the film formed simultaneously with the oxide semiconductor layer 240 may contain impurities or oxygen vacancies. By this, it is possible to give conductivity to the conductive layer 250, and the conductive layer 25 Typical examples of impurities contained in 0 are rare gases, hydrogen, boron, nitrogen, fluorine, aluminum, Typical examples of noble gases are helium, neon, argon, and The conductive layer 250 shown in the example has conductivity. However, one aspect of the present invention is not limited to this. The conductive layer 250 does not necessarily have to be made conductive. The oxide semiconductor layer 240 may have similar properties.

[0169] As described above, the oxide semiconductor layer 240 and the conductive layer 250 are both formed on the insulating layer 130. However, the impurity concentration is different. For example, in the oxide semiconductor layer 240, the impurity concentration is The resulting hydrogen concentration is 5×10 19 atoms / cm 3 Less than or equal to 5 x 10 1 8 atoms / cm 3 or less, more preferably 1 × 10 18 atoms / cm 3 Below, More preferably 5 x 10 17 atoms / cm 3 Less than 1 × 10 16 atoms / cm 3On the other hand, in the conductive layer 250, the following was obtained by secondary ion mass spectrometry: The hydrogen concentration is 8×10 19 atoms / cm 3 or more, preferably 1 × 10 20 atom s / cm 3 More preferably, 5 × 10 20 atoms / cm 3 That's all. The hydrogen concentration in the conductive layer 250 is twice or ten times higher than that in the oxide semiconductor layer 240. That's all.

[0170] The conductive layer 250 has a lower resistivity than the oxide semiconductor layer 240. is 1×10 of the resistivity of the oxide semiconductor layer 240. -8 1×10 times more -1 Less than double is preferred, typically 1×10 -3 Ωcm or more 1×10 4 Less than Ωcm or resistivity 1×10 -3 Ωcm or more 1×10 -1 It is preferable that the resistivity is less than Ωcm.

[0171] The oxide semiconductor film formed simultaneously with the oxide semiconductor layer 240 is exposed to plasma. The oxide semiconductor film can be damaged and oxygen vacancies can be formed. When a film is formed on the conductive film by plasma CVD or sputtering, an oxide semiconductor The film is exposed to plasma to create oxygen vacancies, or to form openings in the insulating layer 170. In the etching treatment for forming the oxide semiconductor film, the oxide semiconductor film is exposed to plasma, and oxygen deficiency occurs. Alternatively, when the oxide semiconductor film is heated in a gas atmosphere containing a mixed gas of oxygen and hydrogen, hydrogen, a rare gas, or When exposed to plasma such as ammonia, oxygen vacancies are generated. By adding impurities to the oxide semiconductor film, oxygen vacancies are formed. The methods of adding impurities include ion doping, ion implantation, and plating. In the case of plasma treatment, the plasma is heated in a gas atmosphere containing the impurities to be added. By generating a plasma and performing plasma processing, the accelerated impurity ions are converted into oxides. By colliding with the semiconductor film, oxygen vacancies can be formed in the oxide semiconductor film.

[0172] An impurity, for example, hydrogen, is added to an oxide semiconductor film in which oxygen vacancies are formed by adding an impurity element. When oxygen is contained, hydrogen enters the oxygen vacancy site and a donor level is formed near the conduction band. As a result, the oxide semiconductor film becomes highly conductive and becomes a conductor. The oxide semiconductor layer 240 can be called an oxide conductor film. It can be said that the conductive layer 250 is formed of an oxide conductive film. The conductive layer 250 can be said to be formed of a highly conductive oxide semiconductor film. It can also be said that it is formed from a highly conductive metal oxide film.

[0173] The insulating layer 180 preferably contains hydrogen. Therefore, when the insulating layer 180 contains hydrogen, the hydrogen in the insulating layer 180 is absorbed by the oxide semiconductor layer The oxide semiconductor film 240 can be formed at the same time as the oxide semiconductor film 240. Impurities can be added to the oxide semiconductor film formed simultaneously with the semiconductor layer 240.

[0174] Furthermore, the insulating layer 170 is an oxide insulating layer containing more oxygen than the stoichiometric composition. Preferably, the insulating layer 180 is formed of an insulating film containing hydrogen. Oxygen contained in the layer 170 moves to the oxide semiconductor layer 240 of the transistor 60, The amount of oxygen vacancies in the oxide semiconductor layer 240 can be reduced, and fluctuations in the electrical characteristics of the transistor 60 can be reduced. At the same time, hydrogen contained in the insulating layer 180 moves to the conductive layer 250, The conductivity of the material can be increased.

[0175] By the above method, the conductive layer 250 is formed simultaneously with the oxide semiconductor layer 240, and after the formation, the conductive layer 250 is By adopting this configuration, it is possible to reduce the manufacturing cost.

[0176] The conductive layer 250 is formed simultaneously with the oxide semiconductor layer 240, and is provided with conductivity after the formation. By adopting this configuration, it is possible to reduce manufacturing costs.

[0177] Conductive layer 1250 can be made conductive in the same manner as conductive layer 250 .

[0178] Insulation layer 600 The insulating layer 600 also functions as a planarizing film. Oil, acrylic resin, polyimide amide resin, benzocyclobutene resin, polyamide resin, It is made of heat-resistant organic materials such as epoxy resin. The insulating layer 600 may be formed by stacking a plurality of insulating films formed by the insulating layer. The configuration may be such that 600 is not provided.

[0179] 《Light blocking layer 630》 A material having a light-shielding property can be used for the light-shielding layer 630. For example, a resin in which a pigment is dispersed can be used. In addition to resin containing dye, inorganic films such as black chrome films can be used for the light-shielding layer 630 . Carbon black, inorganic oxides, composite oxides including solid solutions of multiple inorganic oxides, etc. are used as a light-shielding layer. Can be used for 630.

[0180] 《Colored layer 650》 The colored layer 650 is a colored layer that transmits light of a specific wavelength band, for example, red, green, or blue. A color filter that transmits light in the yellow or yellow wavelength band can be used. The color layer is made of various materials using printing, inkjet, and photolithography methods. The white pixels are formed at the desired positions by etching or other methods. A transparent or white resin may be placed on top of the substrate.

[0181] Spacer 350 An insulating material can be used for the spacer 350. For example, an inorganic material, an organic material, or Alternatively, a material in which an inorganic material and an organic material are laminated can be used. Films containing silicon or silicon nitride, acrylic, polyimide, or photosensitive resin Grease etc. can be applied.

[0182] FPC900 The FPC 900 is electrically connected to the conductive layer 2190 via the anisotropic conductive film 910. In addition, the conductive layer 2190 is formed in the process of forming an electrode layer of the transistor 1060 or the like. Image signals and the like are transmitted from the FPC 900 to the transistor 1060 and the capacitor element 107. 0, etc. can be supplied to a circuit 30 (drive circuit).

[0183] <Modifications of the Transistor 1060> A modification of the transistor 1060 will be described with reference to FIG. 10. The transistor shown in FIG. is characterized by a dual gate structure.

[0184] 10A to 10C are top views and diagrams of a transistor 1060 included in a semiconductor device. 10A is a top view of the transistor 1060, and FIG. 10B is a cross-sectional view of the transistor 1060. 10(A) is a cross-sectional view taken along the dashed line B-B' in FIG. 10(A), and FIG. 10(C) is a cross-sectional view taken along the dashed line B-B' in FIG. 10A is a cross-sectional view taken along the dashed line CC'. For clarity, in FIG. 10A, the substrate 10 0, insulating layer 110, insulating layer 1130, insulating layer 1170, insulating layer 1180, adhesive layer 400, etc. etc. are omitted.

[0185] The transistor 1060 shown in FIGS. 10A to 10C has a gate insulating layer 110. A conductive layer 1120 having a function as an electrode, and a gate insulating film on the conductive layer 1120 The insulating layer 1130 has a function as a conductive layer. The insulating layer 1130 overlaps the conductive layer 1120. an oxide semiconductor layer 1240 formed between the conductive layers 1150 and the oxide semiconductor layer 1240; 1160, the oxide semiconductor layer 1240, the pair of conductive layers 1150, 1160, and the insulating layer 11 70, an insulating layer 1180 on the insulating layer 1170, and a back gate on the insulating layer 1180. The conductive layer 1120 has a function as a conductive electrode. 30, 1170, 1180 are connected to the conductive layer 1230 in the openings 1260. You can also do this.

[0186] Conductive layer 1230 The conductive layer 1230 is a conductive film that is transparent to visible light or a conductive film that is reflective to visible light. The conductive film is formed using a conductive film that is transparent to visible light, for example, Using a material containing one of the following elements: indium (In), zinc (Zn), and tin (Sn) In addition, as a conductive film that transmits visible light, a typical example is an indium Tin oxide, indium oxide with tungsten oxide, indium oxide with tungsten oxide Indium zinc oxide, indium oxide with titanium oxide, indium tin oxide with titanium oxide Conductive oxides such as indium zinc oxide, indium tin oxide with silicon oxide As a conductive film that is reflective to visible light, for example, aluminum Materials containing aluminum or silver can be used.

[0187] As shown in FIG. 10C, the oxide semiconductor layer 1240 is The surface of the insulating layer 11 faces the conductive layer 1230, so that the insulating layer 11 70 and the interface between the insulating layer 1130 and the semiconductor layer 1140, as well as inside the semiconductor layer 1140. Since carriers flow even in the transistor 1060, the amount of carrier movement in the transistor 1060 increases. As a result, the on-state current of the transistor 1060 increases and the field effect mobility In addition, the electric field of the conductive layer 1230 is high on the side surface of the semiconductor layer 1140, or on the side surface and its This affects the edges, including the adjacent edges, resulting in parasitic channels at the sides or edges of the semiconductor layer 1140. The occurrence of bubbles can be suppressed.

[0188] The transistor shown in FIG. 10 has a higher electric field strength than the transistors shown in FIGS. 2(A) and 2(B). Therefore, the gate driver circuit 30 has a high on-state current and a high on-state mobility. By using a transistor with the structure shown in Figure 10 as a transistor to be used, high-speed operation can be achieved. In addition, the area occupied by the circuit 30 can be reduced. This makes it possible to increase the area of ​​the circuit 20 (pixel portion).

[0189] 10 may be used as the transistor 60 in the circuit 20. By providing a transistor with a large on-current in the circuit 20 (pixel portion), a large display device or To reduce signal delay in each wiring even when the number of wirings increases in a high-definition display device This makes it possible to suppress display defects such as display unevenness.

[0190] Note that all the transistors 1060 in the circuit (such as a gate driver) have the same structure. In addition, the plurality of transistors in the circuit (pixel portion) may The transistors 60 may all have the same structure, or may have two or more different structures.

[0191] Alternatively, the transistor described in this embodiment may be a transistor including an oxide semiconductor. However, one embodiment of the present invention is not limited to this. Alternatively, depending on the situation, one embodiment of the present invention may be a semiconductor device using a semiconductor material other than an oxide semiconductor. A transistor may also be used.

[0192] For example, a transistor using a group 14 element, a compound semiconductor, or an oxide semiconductor in the semiconductor layer Specifically, semiconductors containing silicon, semiconductors containing gallium arsenide, Alternatively, a transistor using an organic semiconductor or the like can be applied.

[0193] For example, single crystal silicon, polysilicon, or amorphous silicon may be used for the transistor. This can be applied to semiconductor layers.

[0194] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. .

[0195] (Embodiment 5) The structure of the oxide semiconductor film will be described below.

[0196] Oxide semiconductor films are classified into non-single-crystal oxide semiconductor films and single-crystal oxide semiconductor films. Alternatively, oxide semiconductors can be divided into, for example, crystalline oxide semiconductors and amorphous oxide semiconductors. do.

[0197] As a non-single-crystal oxide semiconductor, CAAC-OS (C Axis Aligned Crystalline Oxide Semiconductor, polycrystalline oxide Semiconductors, microcrystalline oxide semiconductors, amorphous oxide semiconductors, etc. The materials include single-crystalline oxide semiconductors, CAAC-OS, polycrystalline oxide semiconductors, and microcrystalline oxides. Semiconductors, etc.

[0198] First, the CAAC-OS film will be described.

[0199] The CAAC-OS film is one of oxide semiconductor films having a plurality of crystal parts aligned along the c-axis.

[0200] Transmission Electron Microscope (TEM) A bright-field image and a combined analysis image of the diffraction pattern of the CAAC-OS film were obtained by using a microscope. By observing the TEM image, multiple crystalline regions can be identified. On the other hand, high-resolution TEM images also reveal clear boundaries between crystalline parts, i.e., grain boundaries. Therefore, the CAAC-OS film is It can be said that the decrease in electron mobility caused by grain boundaries is unlikely to occur.

[0201] When a high-resolution TEM image of the cross section of the CAAC-OS film was observed from a direction approximately parallel to the sample surface, It can be seen that the metal atoms are arranged in layers in the crystalline part. Each layer of metal atoms is The CAAC-OS film is formed on a surface (also called a surface to be formed) or on a surface that reflects the unevenness of the surface. The CAAC-OS film has a shape and is aligned parallel to the surface on which the film is formed or the upper surface.

[0202] On the other hand, a high-resolution TEM image of the plane of the CAAC-OS film was observed from a direction approximately perpendicular to the sample surface. It was confirmed that the metal atoms in the crystals were arranged in a triangular or hexagonal shape. However, there is no regularity in the arrangement of metal atoms between different crystal parts.

[0203] X-ray diffraction (XRD) was performed on the CAAC-OS film. For example, a CAAC-OS film with InGaZnO4 crystals was found by structural analysis using the device. In the out-of-plane analysis, a peak was observed at a diffraction angle (2θ) of approximately 31°. This peak is attributed to the (009) plane of the InGaZnO4 crystal. Therefore, the crystals of the CAAC-OS film have a c-axis orientation, and the c-axis is approximately aligned on the surface on which the film is formed or on the upper surface. You can see that it is oriented vertically.

[0204] In addition, the out-of-plane method of CAAC-OS film with InGaZnO4 crystals In the analysis by , in addition to the peak at 2θ around 31°, a peak also appeared at 2θ around 36°. The peak at 2θ around 36° is due to the presence of c-axis orientation in part of the CAAC-OS film. The CAAC-OS film contains crystals that do not have a 2θ of around 31°. It is preferable that the peak is exhibited at 2θ of around 36° and that the peak is not exhibited at 2θ of around 36°.

[0205] The CAAC-OS film is an oxide semiconductor film with a low concentration of impurities. These are elements other than the main components of the oxide semiconductor film, such as silicon and transition metal elements. The elements that bond to oxygen more strongly than the metal elements that constitute the oxide semiconductor film, such as fluorine, are oxidized. By removing oxygen from the oxide semiconductor film, the atomic arrangement of the oxide semiconductor film is disrupted, reducing its crystallinity. In addition, heavy metals such as iron and nickel, argon, and carbon dioxide have an atomic radius (or molecular radius) is large, and when it is contained inside the oxide semiconductor film, The impurities contained in the oxide semiconductor film are likely to disturb the atomic arrangement and cause a decrease in crystallinity. Objects can act as carrier traps or carrier sources.

[0206] The CAAC-OS film is an oxide semiconductor film with a low density of defect states. Oxygen vacancies in the semiconductor film can become carrier traps or trap hydrogen, It can be a source of carrier generation.

[0207] Low impurity concentration and low defect level density (low oxygen vacancies) are called high purity intrinsic or The term "substantially highly purified intrinsic" refers to a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film. Since there are fewer carrier generation sources, the carrier density can be reduced. The transistor using the oxide semiconductor film has electrical characteristics ( It is also called normally-on.) It is rare for it to become a high-purity intrinsic or substantially high-purity The intrinsic oxide semiconductor film has few carrier traps. Transistors using this film have little fluctuation in electrical characteristics and are highly reliable. Note that it takes time for the charges trapped in the carrier traps in the oxide semiconductor film to be released. The impurity concentration is high and the charge is stable for a long time, so the charge may behave like a fixed charge. Therefore, a transistor using an oxide semiconductor film with a high density of defect states has unstable electrical characteristics. This may occur.

[0208] In addition, transistors using CAAC-OS films show improved electrical characteristics when irradiated with visible light or ultraviolet light. The fluctuation is small.

[0209] Next, a microcrystalline oxide semiconductor film will be described.

[0210] The microcrystalline oxide semiconductor film has a region where crystals can be confirmed in a high-resolution TEM image. The microcrystalline oxide semiconductor film has a crystal structure including a crystal region and a crystal region where no clear crystal part can be identified. The crystal part contained in the crystal has a size of 1 nm to 100 nm or 1 nm to 10 nm. In particular, the fine particles are often between 1 nm and 10 nm, or between 1 nm and 3 nm. The oxide semiconductor film having nanocrystals (nc) is called nc -OS(nanocrystalline oxide semiconductor) In addition, the nc-OS film has clearly defined grain boundaries in high-resolution TEM images. It may not be possible to recognize it.

[0211] The nc-OS film is a microscopic region (e.g., a region of 1 nm to 10 nm, especially a region of 1 nm or more). The nc-OS film has a periodic atomic arrangement in the region of 3 nm or less. There is no regularity in the crystal orientation between the crystal parts. Therefore, no orientation is observed throughout the film. Therefore, the nc-OS film cannot be distinguished from an amorphous oxide semiconductor film depending on the analysis method. For example, X-ray diffraction (XR) using X-rays with a diameter larger than that of the crystals is used for nc-OS films. When structural analysis is performed using the D device, the crystal plane is In addition, the peaks indicating the probes larger than the crystalline part were not detected in the nc-OS film. Electron diffraction (also called selected area electron diffraction) using an electron beam with a diameter (for example, 50 nm or more) When the diffraction pattern is changed to 0.05μm, a halo-like diffraction pattern is observed. Nanobeam electrons are used, which use an electron beam with a probe diameter close to or smaller than the size of the crystal part. When diffraction is performed, spots are observed. If you do this, you may observe a circular (ring-shaped) area of ​​high brightness. When nanobeam electron diffraction was performed on the nc-OS film, multiple spots were observed within the ring-shaped region. It may be observed.

[0212] The nc-OS film is an oxide semiconductor film with higher order than an amorphous oxide semiconductor film. Therefore, the nc-OS film has a lower density of defect states than the amorphous oxide semiconductor film. In the nc-OS film, there is no regularity in the crystal orientation between different crystal parts. The S film has a higher defect state density than the CAAC-OS film.

[0213] Next, the amorphous oxide semiconductor film will be described.

[0214] The amorphous oxide semiconductor film has an irregular atomic arrangement in the film and is an oxide film that does not have a crystalline portion. An example is an oxide semiconductor film that has an amorphous state, such as quartz.

[0215] In the amorphous oxide semiconductor film, no crystalline portion can be confirmed in a high-resolution TEM image.

[0216] When the structure of the amorphous oxide semiconductor film is analyzed using an XRD device, out-of-p In the analysis by the Lane method, no peaks indicating crystal planes were detected. When electron diffraction is performed on a conductive film, a halo pattern is observed. When nanobeam electron diffraction is performed on a conductive film, no spots are observed, and a halo pattern is observed. Observed.

[0217] The oxide semiconductor film has a structure that exhibits physical properties between the nc-OS film and the amorphous oxide semiconductor film. An oxide semiconductor film having such a structure may be used, particularly, for amorphous-like oxidation. Amorphous-like Oxide Semiconductor (a-like OS) The membrane is called a conductor membrane.

[0218] In the a-like OS film, voids are observed in high-resolution TEM images. In addition, crystals can be clearly seen in high-resolution TEM images. The a-like OS film has a region where the crystal part is not observed and a region where the crystal part is not observed. Crystallization occurs due to the small amount of electron irradiation, which is the level observed with a TEM, and the growth of the crystals can be seen. On the other hand, if the nc-OS film is of good quality, the small amount of charge observed by TEM can be detected. Almost no crystallization due to electron irradiation is observed.

[0219] The size of the crystalline parts of the a-like OS film and the nc-OS film was measured using a high-resolution T This can be done using EM images. For example, InGaZnO4 crystals have a layered structure, There are two Ga-Zn-O layers between the In-O layers. The structure has three In-O layers and six Ga-Zn-O layers, for a total of nine layers aligned in the c-axis direction. Therefore, the spacing between these adjacent layers is The lattice spacing (also called the d value) is approximately the same as the value of 0.29 nm from crystal structure analysis. Therefore, we focused on the lattice fringes in high-resolution TEM images and calculated the spacing between the lattice fringes. In the region where the distance is between 0.28 nm and 0.30 nm, each lattice fringe is InG aIt corresponds to the ab plane of the ZnO4 crystal.

[0220] In addition, the density of an oxide semiconductor film may differ depending on the structure. If the composition of the membrane is known, the density can be determined by comparing it with that of a single crystal with the same composition. The structure of the oxide semiconductor film can be estimated. The density of the OS-like film is 78.6% or more and less than 92.3%. The density of the nc-OS film and the CAAC-OS film was 92.3% or more. Note that an oxide semiconductor film having a density of less than 78% of the density of a single crystal is The film formation itself is difficult.

[0221] The above will be explained using a specific example. For example, In:Ga:Zn=1:1:1 [atomic In the oxide semiconductor film that satisfies the numerical ratio, single crystal InGaZnO4 with a rhombohedral crystal structure The density of 3 Therefore, for example, In:Ga:Zn=1:1:1 In an oxide semiconductor film that satisfies the atomic ratio, the density of the a-like OS film is 5.0g / cm 3 More than 5.9g / cm 3 For example, In:Ga:Zn=1:1: In the oxide semiconductor film satisfying the atomic ratio of 1, the density and CAAC- The density of the OS film is 5.9 g / cm 3 More than 6.3g / cm 3 It will be less than.

[0222] In some cases, single crystals with the same composition do not exist. In such cases, crystals with different compositions at any ratio are used. By combining single crystals, it is possible to calculate the density corresponding to a single crystal of the desired composition. The density of a single crystal of a desired composition can be determined by the ratio of the single crystals of different compositions combined. However, the density should be calculated using as few types of single crystals as possible. It is preferable to calculate them in combination.

[0223] The oxide semiconductor film may be, for example, an amorphous oxide semiconductor film, an a-like OS film, or a finely crystalline oxide semiconductor film. The film may be a stacked film including two or more of a crystalline oxide semiconductor film and a CAAC-OS film.

[0224] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. .

[0225] (Sixth embodiment) In this embodiment, a structural example of a display device according to one embodiment of the present invention will be described with reference to FIGS. .

[0226] [Configuration example] FIG. 11A is a top view of a display device according to one embodiment of the present invention, and FIG. 11B is a top view of a display device according to one embodiment of the present invention. A pixel circuit that can be used when a liquid crystal element is applied to a pixel of a display device of one embodiment will be described. 11C is a circuit diagram showing a pixel of a display device according to one embodiment of the present invention. 1 is a circuit diagram illustrating a pixel circuit that can be used when an organic EL element is applied. .

[0227] The transistors arranged in the pixel portion can be formed according to the above embodiment modes. Since the transistor can be easily made into an n-channel type, the n-channel transistor in the driver circuit can be easily made into an n-channel type. A part of the driver circuit can be configured with a transistor of the same type as the transistor of the pixel part. In this way, the transistor shown in the above embodiment is formed in the pixel portion or the driver circuit. By using the above, a highly reliable display device can be provided.

[0228] An example of a top view of an active matrix display device is shown in FIG. On the surface of 700, there are a pixel portion 701, a scanning line driving circuit 702, a scanning line driving circuit 703, a signal line driving circuit 704, a signal line driving circuit 705, a signal line driving circuit 706, a signal line driving circuit 707, a signal line driving circuit 708, a signal line driving circuit 709, a signal line driving circuit 710, a signal line driving circuit 711, a signal line driving circuit 71 The pixel portion 701 has a signal line driver circuit 704. A plurality of signal lines are extended from the signal line driver circuit 704. A plurality of scanning lines are connected to a scanning line driving circuit 702 and a scanning line driving circuit 703. The scanning lines and the signal lines are arranged in such a manner that they extend from each other. The display device has a substrate 700 that is connected to a flexible printed circuit board (FPC) or the like. It is connected to a timing control circuit (also called a controller or control IC) via a connection. do.

[0229] In FIG. 11A, a scanning line driver circuit 702, a scanning line driver circuit 703, a signal line driver circuit 70 4 is formed on the same substrate 700 as the pixel portion 701. Since the number of components such as the above is reduced, costs can be reduced. When an operating circuit is provided, it becomes necessary to extend the wiring, which increases the number of connections between the wiring. If a drive circuit is provided on the 700, the number of connections between the wiring can be reduced, improving reliability. Furthermore, the yield can be improved.

[0230] [Liquid crystal display device] An example of the circuit configuration of a pixel is shown in FIG. 11(B). 1 shows a pixel circuit that can be applied to a pixel of a display device.

[0231] This pixel circuit can be applied to a configuration in which one pixel has multiple pixel electrode layers. The pixel electrode layer is connected to different transistors, and each transistor is driven by a different gate signal. This allows individual pixels in a multi-domain design to The signals applied to the electrode layers can be controlled independently.

[0232] The gate wiring 712 of the transistor 716 and the gate wiring 713 of the transistor 717 are , are separated so that different gate signals can be applied. is used in common for transistor 716 and transistor 717. The transistors 16 and 717 may be any of the transistors described in the above embodiment modes. This makes it possible to provide a highly reliable liquid crystal display device.

[0233] The transistor 716 is electrically connected to a first pixel electrode layer. The second pixel electrode layer is electrically connected to the first pixel electrode layer 17. The first pixel electrode layer and the second pixel electrode layer are separated from each other. There is no particular limitation to the shape of the first pixel electrode layer. For example, the first pixel electrode layer may be V-shaped.

[0234] The gate electrode of the transistor 716 is connected to the gate wiring 712, and the gate electrode of the transistor 717 is connected to the gate wiring 712. The gate electrode is connected to the gate wiring 713. By giving different gate signals to the transistors 716 and 717, the operation timing of the transistors 716 and 717 is By varying the polarity, the orientation of the liquid crystal can be controlled.

[0235] Also, the capacitor wiring 710, the gate insulating film functioning as a dielectric, and the first pixel electrode layer or A storage capacitor may be formed by a capacitor electrode electrically connected to the second pixel electrode layer.

[0236] The multi-domain structure has a first liquid crystal element 718 and a second liquid crystal element 719 in one pixel. The first liquid crystal element 718 is composed of a first pixel electrode layer, a counter electrode layer, and a liquid crystal layer therebetween. The second liquid crystal element 719 is composed of a second pixel electrode layer, a counter electrode layer, and a liquid crystal layer therebetween. do.

[0237] Note that the pixel circuit shown in FIG. 11(B) is not limited to this. The pixel may contain new switches, resistors, capacitors, transistors, sensors, or logic circuits. etc. may be added.

[0238] [Organic EL display device] Another example of the circuit configuration of a pixel is shown in Figure 11(C). 1 shows the pixel structure of the device.

[0239] In an organic EL element, when a voltage is applied to the light-emitting element, electrons are released from one of the pair of electrodes. Holes are injected from the other side into the layer containing the light-emitting organic compound, causing a current to flow. The recombination of electrons and holes causes the light-emitting organic compound to form an excited state, which This mechanism is what causes this type of luminescence. The element is called a current-excited light-emitting element.

[0240] FIG. 11C is a diagram showing an example of an applicable pixel circuit. An example in which two transistors are used in one pixel is shown. The film can be used for the channel formation region of an n-channel transistor. The pixel circuit can be applied with digital time gray scale driving.

[0241] Regarding the configuration of applicable pixel circuits and pixel operation when digital time gray scale driving is applied, and explain.

[0242] The pixel 720 includes a switching transistor 721, a driving transistor 722, and a light-emitting element The switching transistor 721 has a gate electrode 724 and a capacitor element 723. The source electrode layer is connected to the scanning line 726, and the first electrode (the source electrode layer and the drain electrode layer) The second electrode (the other of the source electrode layer and the drain electrode layer) is connected to the signal line 725. ) is connected to the gate electrode layer of the driving transistor 722. 22, the gate electrode layer is connected to a power supply line 727 via a capacitor element 723, and the first electrode is connected to a power supply line 727. The second electrode is connected to the first electrode (pixel electrode) of the light emitting element 724. The second electrode of the light emitting element 724 corresponds to the common electrode 728. It is electrically connected to a common potential line formed on the substrate.

[0243] The switching transistor 721 and the driving transistor 722 may be of other embodiments. This allows for the development of highly reliable organic EL devices. A display device can be provided.

[0244] The potential of the second electrode (common electrode 728) of the light-emitting element 724 is set to a low power supply potential. The power supply potential is a potential lower than the high power supply potential supplied to the power supply line 727, for example, GND , 0V, etc. can be set as the low power supply potential. The high power supply potential and the low power supply potential are set so that the potential difference is equal to or greater than the threshold voltage. By applying a voltage to the light emitting element 724, a current flows through the light emitting element 724, causing it to emit light. The forward voltage in 4 refers to the voltage required to achieve the desired brightness, and is at least the forward threshold. Includes low voltages.

[0245] The capacitor 723 can be saved by substituting the gate capacitance of the driving transistor 722. The gate capacitance of the driving transistor 722 can be omitted. A capacitance may be formed between the electrode layer and the insulating layer.

[0246] Next, a signal input to the driving transistor 722 will be described. In this case, the driving transistor 722 is either fully on or fully off. A video signal such as this is input to the driving transistor 722. In order to operate the drive transistor 722 in the linear region, a voltage higher than the voltage of the power supply line 727 is applied to the drive transistor 722. A signal line 725 is connected to the gate electrode layer of the transistor 722. A voltage equal to or greater than the threshold voltage Vth of the input transistor 722 is applied.

[0247] When analog gradation driving is performed, the gate electrode layer of the driving transistor 722 is connected to the light emitting element 72 A voltage equal to or greater than the sum of the forward voltage of the transistor 724 and the threshold voltage Vth of the driving transistor 722 is applied. In addition, a video signal is input so that the driving transistor 722 operates in the saturation region. A current flows through the light emitting element 724. In addition, the driving transistor 722 is operated in a saturation region. In order to achieve this, the potential of the power supply line 727 is set higher than the gate potential of the driving transistor 722. By converting the video signal into an analog signal, a current corresponding to the video signal is passed through the light emitting element 724. , analog gray scale driving can be performed.

[0248] The configuration of the pixel circuit is not limited to the pixel configuration shown in FIG. (C) The pixel circuit shown in FIG. 1 includes a switch, a resistor, a capacitor, a sensor, a transistor, or a logic element. A logic circuit or the like may be added.

[0249] When the transistor illustrated in the above embodiment is applied to the circuit illustrated in FIG. The source electrode (first electrode) is on the low potential side, and the drain electrode (second electrode) is on the high potential side. Furthermore, the potential of the first gate electrode is controlled by a control circuit or the like. The second gate electrode is supplied with a potential lower than that applied to the source electrode by a wiring (not shown). Any of the above-mentioned potentials may be input.

[0250] For example, in this specification and the like, the term "display element," "display device having a display element," "light emitting element," "light emitting device," "light emitting element ... A light-emitting device, which is a device having a light-emitting element and a light-emitting element, can be used in various forms or in various The display element, the display device, the light-emitting element or the light-emitting device may include, for example, For example, EL (electroluminescence) elements (EL elements containing organic and inorganic materials, organic EL elements, inorganic EL elements), LEDs (white LEDs, red LEDs, green LEDs, blue LEDs) etc.), transistors (transistors that emit light according to the current), electron-emitting elements, liquid crystal elements , electronic ink, electrophoretic element, grating light valve (GLV), plasma display Using MEMS (Micro-Electro-Mechanical Systems) Display element, Digital Micromirror Device (DMD), DMS (Digital Micromirror Shutter), MIRASOL (registered trademark), IMOD (Interference Module MEMS display element, shutter button type MEMS display element, optical interference type MEMS display element display element, electrowetting element, piezoelectric ceramic display, carbon nanotube In addition to these, it has at least one electrical or A display medium whose contrast, brightness, reflectivity, transmittance, etc. change due to magnetic or other factors. An example of a display device using an EL element is an EL display. An example of a display device using electron-emitting elements is a field emission display. Flat panel display (FED) or SED (Surface-on Display) Induction Electron-emitter Displays (ELDs) are also available. An example of a display device using a liquid crystal element is a liquid crystal display (transmissive liquid crystal display, Transflective LCD, Reflective LCD, Direct-view LCD, Projection LCD LCDs, electronic ink, electronic powder, or electrophoresis An example of a display device using the element is electronic paper. When realizing a reflective LCD or a reflective type LCD, part or all of the pixel electrodes For example, a part of the pixel electrode or In this case, the entire surface may be made of aluminum, silver, etc. It is also possible to provide a memory circuit such as an SRAM under the projection electrode. When using LEDs, the LED electrodes and nitrides Graphene or graphite may be placed under the semiconductor. In this way, graphene or graphite can be used as a multilayer film by stacking multiple layers. By providing the nitride semiconductor, for example, a crystal-containing n-type GaN semiconductor layer, Furthermore, a p-type GaN semiconductor having crystals can be formed on the surface. By providing layers, LEDs can be constructed. An AlN layer may be provided between the n-type GaN semiconductor layer having crystals. The GaN semiconductor layer may be formed by MOCVD. Therefore, the GaN semiconductor layer of the LED can also be formed by sputtering.

[0251] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. .

[0252] (Embodiment 7) In this embodiment, one of electronic devices to which the display device of one embodiment of the present invention can be applied will be described. An example will be described with reference to FIG.

[0253] As an electronic device to which a display device is applied, for example, a television device (television or television (also called television receivers), computer monitors, digital cameras, digital video Cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), mobile phones These include portable game machines, mobile information terminals, sound reproduction devices, and large game machines such as pachinko machines. Specific examples of these electronic devices are shown in Figure 12.

[0254] FIG. 12A shows a portable game machine, which includes a housing 7101, a housing 7102, a display portion 7103, Display unit 7104, microphone 7105, speaker 7106, operation keys 7107, stylus The display device according to one embodiment of the present invention includes the display portion 7103 or the display portion 7108. 104. The display portion 7103 or the display portion 7104 can be used in accordance with one embodiment of the present invention. By using such a light emitting device, a mobile phone having excellent usability and less deterioration in quality can be provided. It is possible to provide a portable game machine. The display unit 7103 and the display unit 7104 are included in the portable game machine. The number is not limited to this.

[0255] FIG. 12B shows a smartwatch, which includes a housing 7302, a display portion 7304, and operation buttons. 7311, 7312, a connection terminal 7313, a band 7321, a clasp 7322, etc. The display device according to one embodiment of the present invention can be used for the display portion 7304.

[0256] FIG. 12C shows a portable information terminal, which includes a display portion 7502 incorporated in a housing 7501. , operation button 7503, external connection port 7504, speaker 7505, microphone 7506 The display device according to one embodiment of the present invention can be used for the display portion 7502. Cut.

[0257] FIG. 12D shows a video camera, which includes a first housing 7701, a second housing 7702, a display unit 77 03, operation keys 7704, a lens 7705, a connection part 7706, etc. The lens 7705 and the display unit 7703 are provided in the first housing 7701. The first housing 7701 and the second housing 7702 are connected to each other. The first housing 7701 and the second housing 7702 are connected by a portion 7706, and the angle between the first housing 7701 and the second housing 7702 is The image on the display unit 7703 can be changed by the connection unit 7706. 6, and a configuration in which the switching is performed according to the angle between the first housing 7701 and the second housing 7702. The display device according to one embodiment of the present invention can be used for the display portion 7703.

[0258] Note that this embodiment mode can be appropriately combined with other embodiment modes shown in this specification. . [Explanation of symbols]

[0259] C1 Capacitor element 10 Display device 11 Transistor 12 transistors 13 Transistor 20 circuits 30 circuits 40 circuits 60 transistors 70 Capacitor element 100 boards 110 Insulating layer 120 Conductive layer 130 Insulating layer 140 Semiconductor layer 150 conductive layer 160 Conductive layer 165 Insulating Layer 170 Insulating Layer 180 insulating layer 190 Conductive Layer 200 liquid crystal layers 210 Conductive layer 240 Oxide semiconductor layer 241 Oxide semiconductor layer 242 Oxide semiconductor layer 250 conductive layer 300 boards 310 Conductive layer 330 Liquid crystal element 350 spacer 400 adhesive layer 500 touch sensor 600 insulating layer 630 Light blocking layer 650 Colored layer 700 boards 701 Pixel section 702 Scanning line driving circuit 703 Scanning line driving circuit 704 Signal Line Driver Circuit 710 Capacitance wiring 712 Gate wiring 713 Gate wiring 714 data line 716 Transistor 717 Transistor 718 Liquid Crystal Devices 719 Liquid Crystal Devices 720 pixels 721 Switching Transistor 722 Drive transistor 723 Capacitor 724 Light-emitting element 725 signal line 726 scan lines 727 Power line 728 Common electrode 900 FPC 910 Anisotropic Conductive Film 1060 transistor 1070 Capacitive element 1080 Capacitive element 1100 Insulation layer 1110 insulating layer 1120 Conductive layer 1130 Insulating layer 1140 Semiconductor layer 1150 Conductive layer 1160 Conductive layer 1170 Insulation layer 1180 Insulation layer 1190 Conductive layer 1210 Conductive layer 1220 Conductive layer 1230 Conductive layer 1240 Oxide semiconductor layer 1250 conductive layer 1260 opening 1270 opening 1410 Opening 1420 Opening 2150 Conductive layer 2170 Insulation layer 2180 Insulation layer 2190 Conductive layer 7101 Housing 7102 Housing 7103 Display section 7104 Display section 7105 Microphone 7106 Speaker 7107 Operation key 7108 Stylus 7302 Housing 7304 Display section 7311 Operation button 7312 Operation button 7313 Connection terminal 7321 Band 7322 Clasp 7501 Case 7502 Display section 7503 Operation button 7504 External connection port 7505 Speaker 7506 Microphone 7701 Housing 7702 Case 7703 Display section 7704 Operation key 7705 Lens 7706 Connection

Claims

1. A display device having a pixel, a gate driver, and an adhesive layer, the gate driver includes a transistor and a capacitance element; the transistor includes an oxide semiconductor layer in a channel formation region, the capacitor element includes a first conductive layer containing the same metal element as the oxide semiconductor layer, an insulating layer, and a second conductive layer; the second conductive layer has a region located above the first conductive layer; the second conductive layer has a plurality of openings; At least one of the plurality of openings has a long side and a short side, the long side is in a direction parallel to the channel width direction of the transistor, The second conductive layer has a region in contact with the adhesive layer.

2. In claim 1, The first and second conductive layers comprise at least one selected from the group consisting of indium, zinc, and tin.

3. In claim 1 or 2, The insulating layer comprises nitrogen and silicon.

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